Tinting strength

A carbon black test sample is obtained by mixing carbon black and zinc oxide with epoxidized soybean oil. The mixture is milled in a mechanical muller with frequent scraping. The specimen is prepared by film drawdown, roller spreader or by the glass slide method. Reflectometer readings are obtained. The result is a comparison of the tint strength of standard with the test sample expressed in tint 

White pigments are measured in compositions containing a black letdown vehicle using a reflectance measurement. The test pigment is compared with a standard sample.  

There is much compositional freedom in these methods which makes a comparison of results from different sources veiy difficult and unreliable. 

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Hiding power and tinting strength of a pigment also depend on concentration in the organic matrix. The concentration is usually expressed as the pigment volume concentration ... 

InstmmentaHy, both the hiding power and tinting strength can be determined from the amount of the incident light reflectance of coated white and black substrates. Relationships derived from Kubelka and Munk theory (6) are appHed in actual calculations. 

ASTM E20-843 for color strength in ink, and ISO 8781 (parts 1—3) for evaluating tinting strength, fineness of grind, and gloss. 

The tinting strength of mbber-grade carbon blacks shows a linear relationship with shown in Figure 5. Since performance characteristics are... 

Fig. 5. Tinting strength versus median Stokes diameters for a range of reinforcing tread blacks.

Industry classification N2 surface area, m /g Particle diameter, nm Fluffy Pellets Fluffy Pellets Nigrometer index Tinting strength Volatile, % pH... 

There are a number of ways to obtain color in a ceramic material (1). First, certain transition-metal ions can be melted into a glass or dispersed in a ceramic body when it is made. Although suitable for bulk ceramics, this method is rarely used in coatings because adequate tinting strength and purity of color caimot be obtained this way. 

Iron Oxides. In addition to the black iron oxide, there are several natural and synthetic yellow, brown, and red oxides. As a class, they provide inexpensive but dull, lightfast, chemically resistant, and nontoxic colors. The natural products ate known as ocher, sieima, umber, hematite, and limonite. These include varying amounts of several impurities in particular, the umbers contain manganese. Their use is limited because of low chroma, low tinting strength, and poor gloss retention. 

Low Tinting Strength - The zinc borate has a refractive index similar to most organic polymers, which results in the retention of considerable translucency. This provides for easy visual inspection of the finished products and allows the use of lower pigment loadings in formulations requiring deep shades. 

Tinting, of paint, 18 66 Tinting strength, of inorganic pigments, 19 381... 

Table 19.2 Hiding Power and Tinting Strength of Pigments...

Pigment Hiding Power (m /kg) Index of Refraction Tinting Strength... 

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